As medical imaging and analysis techniques are continuously improving, the healthcare professional is presented with an ever increasing complexity of the data available for visualization. Starting with measurements of a parameter within a volume of interest, the parameter may be analyzed in different quantitative ways, for example to extract maximum intensity, mean intensity, minimum intensity, average slope values, maximum slope values, minimum slope values, for any desired piece of the volume of interest. The professional must then be able to visualize the data in a meaningful way. For example, visualization of time-intensity curves and associated quantitative analysis data derived from medical images, such as for images of a diseased heart acquired with first pass enhancement cardiac magnetic resonance imaging (MRI).
At present, two-dimensional (2D) visualization techniques are typically used to visualize such time-intensity curves and the associated quantitative analysis data.
For example, a visualization representation known as a perfusogram for a biological structure is known from US application 2005/0124861. Such a perfusogram representation 10 is depicted in FIG. 7—it comprises a 2D array of pixels 15, each pixel having a grey value or color value to represent a mean intensity level. A key 20 is also depicted indicating the mean intensity associated with each grey value or color value. The number of pixels in the horizontal direction 30 is determined by the number of time intervals for which the mean intensity values are determined. The number of pixels in the vertical direction 40 is determined by the number of segments selected for analysis. In other words, the vertical direction provides spatial information, and the horizontal direction provides temporal information.
Such a perfusogram may be visualized in combination with a color overlay on an anatomical gray value image, so that a healthcare professional may relate the spatial information to the anatomy of the patient. It is also known in the art to overlay the anatomical gray value image with color-coded segments, such that the value of a parameter for that segment may be related to the color chosen to depict that segment. For example, as shown in FIG. 6, a color overlay representation 50 comprises an anatomical gray value image 60 of a human heart, overlaid in the region of the myocardium by at least one colored segment 70. The color of the segment 70 is an indication of the mean segment intensity as a measure of perfusion, and a key 80 is also depicted indicating the mean intensity associated with each color.
FIGS. 6 and 7 illustrate the difficulties in presenting complex multidimensional data to the user—FIG. 7 makes it difficult to relate the representation to the actual anatomy of the patient, and FIG. 6 does not show changes in intensity observed over time.